Welt-type shoes or boots are typically sturdy and resist water, which makes them preferable for outdoor or rigorous environments. As shown in FIG. 1, welt 12 is attached to a perimeter of shoe 10 and stitch 18 passes through rib 16, welt 12, and upper 22 to secure insole 26 and upper 22 to the rest of shoe 10. In this fashion, wear upon stitch 18 is reduced since welt 12 protects stitch 18 from debris or abrasions, which results in a reduction in the likelihood of upper 22 being separated from an outsole placed beneath and attached to midsole 28. Further, a shoe or boot made according to the welt system usually inhibits dirt and other debris from entering the shoe through the attachment of the upper and sole.
Because insole 26, upper 22, and rib 16 are all secured to welt 12 and welt 12 is attached to midsole 28, midsole 28 is generally a rigid and sturdy material to provide a strong enough anchoring mechanism. If midsole 28 is too flexible, stitch 18 or welt 12 may tear away from midsole 28. To improve the comfort of such welted shoes and boots, a cushioning pad may be placed on top of insole 26. However, this may not enhance flexibility and the thickness of the cushioning pad is possibly compromsised due to the limited space within the interior of shoe 10. Moreover, since such cushion is customarily of a uniform thickness, additional cushioning at the key impact areas near the heel and forepart of the shoe or boot may be lacking.
Another disadvantage of conventional welted construction is the welt itself, which typically is semi-rigid or rigid to withstand the forces exerted through the stitching and to secure the sole and upper together with extraordinary strength around the entire shoe. Welt 12 may be a strip of leather, reinforced fabric, or hard rubber. Moreover, the stitching is often concentrated, or densely applied, as it extends around the perimeter of welt 12 because a minimal amount of stitching may cause the stitch to fail, and such concentrated stitching possibly contributes to a reduction in flexibility.
A construction built primarily for comfort usually includes soft and contoured midsoles and outsoles, such as generally used in athletic shoes. In these constructions, an upper is typically molded or cemented directly to the outsole, which is usually contoured or shaped to conform to the wearer's foot and to offer a comfortable fit. Typically, the midsole is constructed of a soft material such as polyurethane or ethylvinyl acetate, which is bonded to an outsole of harder wearing material such as rubber or thermoplastic polyurethane. Although these constructions provide comfortable cushioning for the wearer's foot, the soles normally wear quickly and/or the uppers detach from the soles.
Although different constructions exist for either durability or comfort, there is generally no integrated construction that combines both durability and comfort without compromising either.
What is desired, therefore, is a shoe construction that provides both durability and comfort. Another desire is a durable and comfortable shoe that resists wear and inhibits debris from entering the shoe. A further desire is a shoe with enhanced flexibility.